Recessed light fixture



July 26, 1966 M. H. KRUGER RECESSED LIGHT FIXTURE 3 Sheets-Sheet 1 Filed Nov. 29, 1963 y 6, 1966 M. H. KRUGER RECESSED LIGHT FIXTURE 3 Sheets-Sheet 2 Filed Nov. 29, 1963 July 26, 1966 M. H. KRUGER RECESSED LIGHT FIXTURE 5 Sheets-Sheet 5 Filed NOV. 29, 1963 United States Patent Oftice 3,263,072 Patented July 26, 1966 3,263,072 RECESSED LIGHT FIXTURE Michael Henry Kruger, Chestnut Hill, Mass., assignor to Smithcraft Corporation, Chelsea, Mass, a corporation of Massachusetts Filed Nov. 29, 1963, Ser. No. 326,717 3 Claims. (Cl. 240-5111) This invent-ion relates to fluorescent lighting fixtures of the recessed type, designed to provide a light diffusing surface lying substantially in the plane of the ceiling. More particularly, the invention provides an elongated, recessed fluorescent fixture and light diffusing shield of improved design in which novel means are employed to secure the shield to the fixture proper, giving both esthetic and functional advantages.

The invention is addressed to the need for a simple and economical, yet elegant, recessed lighting fixture displaying only a light diffusing shield in the form of a lighted panel, with no trim or other extraneous lines or substances visible. Modern architectural theories demand such plainness of apperance, but it has heretofore seemed impractical to obtain in an individual fixture installation.

It is true.that luminous ceilings have been employed, turning the entire ceiling into a huge lighted panel with the light source hidden above. But for most buildings such ceilings are too expensive and diflicult to install and maintain. It is more practical to use individual recessed fixtures.

Nevertheless, the problem of constructing a recessed lighting fixture that does not require a visible frame or trim surrounding the lighted panel, though perhaps appearing easy of solution, has never been satisfactorily solved, due to a number of conflicting technological requirements. For example, while the fixture must have no visible means of supporting the diffusing panel, it must at the same time be rugged and capable of being easily opened and closed from the outside by any person however unskilled. Nor can it present visible handles or distinct protrusions to facilitate opening. Additionally, it must be competitive in cost of manufacture with standard fixtures and easy to install.

Because of the failure of the prior art to reconcile these and other requirements the common fixture available today still employs trim members running along the edges of the ceiling recess, overlapping the shield and ceiling. Necessarily, such trim adds extra and intruding lines and surfaces to the ceiling, and usually an extra substance, as the trim is normally of metal; the desired lighted panel appearance is thus destroyed.

It is the principal object of the invention, therefore, to provide new and practical securing means for securing a light diffusing shield to a recessed fixture to produce a plain lighted panel effect.

Another object is to provide such a securing means that lies wholly within the ceiling recess, out of the line of light flowing toward the panel and yet is subject to control from outside the recess, with the panel lying substantially in the plane of the ceiling.

Another object is to provide a securing means of the above type that precisely centers the panel, both vertically and horizontally, to avoid even slight error, which would be visible to the observer as a crooked line, a protruding edge, or a ray of light escaping from a crack between the panel and the ceiling.

Still another object is to provide for masking the edges of the ceiling recess no longer covered by the usual metal trim, providing a smooth transition between the substances of the ceiling and the panel, with a clean line of contrast between light and darkness.

Finally, it is an object of the invention to achieve all of the above for all sizes of panels and at the same or little greater cost than that of presently available fixtures.

To facilitate understanding of the invention, its preferred embodiment is shown in the accompanying drawings, in which:

FIG. 1 is a side view showing the panel in its installed position, the left-hand portion of the main housing being cut away;

FIG. 2 is the same side view as in FIG. 1, but with the panel in the extended position;

FIG. 3 is a sectional view taken along the lines 33 in FIG. 1;

FIG. 4 is a sectional view taken along the lines 44 in FIG. 2, the dotted lines showing the shield pivoted and hanging from a single support;

FIG. 5 is an exploded perspective view of the end of the fixture, showing the shield supports extended, with one side of the shield unhooked;

FIG. 6 is a sectional view of one side of the fixture taken along the lines 66 in FIG. 2, showing in detail the interconnection of the shield, shield support and arms; and

FIG. 7 is a side view showing in solid and dotted lines successive positions A, B and C of the arms and the shield support moving from the extended to the retracted position.

Referring to the drawings, the fixture comprises a main housing 10 supported in the ceiling recess, above the lower surface of the ceiling 11, by well-known adjustable supporting means 40 (FIGS. 3, 4), the supporting means 40 resting on inverted T blocks or other ceiling structure not shown and forming no part of the invention. The numeral 44 indicates a point of connection between the main housing 10 and the supporting means 40.

According to the invention two elongated shield supports 30 are connected to the inner sides of the main housing by resilient means indicated generally at 50 in FIG. 5 and described in greater detail below. The shield supports 30 have an upper retracted position wholly within the ceiling recess (FIGS. 1, 3), and a lower extended position in which at least the lower edges of the supports protrude below the surface of the ceiling (FIGS. 2, 4, 5). The supports are spaced inwardly from the corresponding edges of the shield.

The light diffusing shield 12, as best shown in FIG. 5, broadly comprises a main transmitting body 14, up wardly and inwardly extending support engaging members 16, laterally extending flanges 18, and end pieces 17.

The support engaging members 16 of the shield and the shield supports 30 in the main housing are respectively provided with cooperating hooking and receiving means 20 and 34, by which means the shield is removably but securely incorporated into the fixture. in the embodiment shown, the hooking means 20 are .in the form of an inverted trough, with the complementary receiving means 34 being in the form of an upright trough. The hooking and receiving means are thus easily interlocked; in addition, when one side of the shield is unhooked from its support, the other side is free to pivot in the trough of its support, thereby enabling the shield to hang from one side in a generally downward position (FIG. 4) while access is provided to the interior of the fixture.

To facilitate the pivoting of the shield in the support trough, the support, in its extended position, should protrude below the ceiling a distance slightly greater than the distance, taken parallel to the main transmitting body 14, between the farthest outward extent of flange 18 and the farthest inward extent of the hooking means 20, properly locating the pivot axis. The upper edge of the shield will then swing clear of the ceiling as it pivots.

The shield is attached to the shield supports 30 while said supports are in their extended position. To this end,

connection means 50 is somewhat flexible laterally, allowing the supports 30 a degree of freedom to flex inwardly horizontally relative to the main housing. In attaching the shield, one side is hooked over its support, the shield is pivoted upwardly and at the same time moved bodily horizontally toward the other support. The already engaged support is thus flexed inwardly, allowing the other side of the shield to swing up and over the other support and to engage it as the shield is lowered and the first support allowed to unflex.

Upward pressure is then applied to the entire shield, which pressure is transmitted to the supports 30 by small ledge members 21, located on the inner surface of end pieces 17, near the corners of the shield. Ledge members 21 are slightly spaced below the supports when the shield hangs free in the extended position, and contact the supports as the shield is moved upwardly, thereby driving the supports upwardly and drawing the shields main transmitting body 14 up to the plane of the ceiling 11. The overall width of the shield is larger than the width of the recess in the ceiling, with the result that the flanges 18 overlap the borders of the recess. The flanges 18 thus serve to limit the upward movement of the shield as well as to cover the edges of the recess.

The shield supports 30 are essentially elongated flat plates 32 with the trough shaped receiving portions 34 extending along their lower edges and directed outwardly from the fixture. The plates 32 extend, at least at their upper edges, along substantially the entire length of the main housing, riding on the inner surface of the housing through small wheels 31 attached to the upper corners of the plates. The ends of the plates 32 preferably are oblique, as shown in FIGS. 3 and 4, thus making them shorter at their lower edges than at their upper edges and eliminating any possible interference between the plate ends and the main housing as the supports move between their extended and retracted positions.

The supports 30 are connected to the main housing 10 by resilient means 59 preferably comprising an overcenter spring mechanism. In the embodiment shown two overcenter spring units are used with each shield support, one toward each end of the support. Each such spring unit includes inner arm 52, outer arm 53, and tension spring 54. The outer arm and the spring are located outside the main housing only as a matter of choice, largely to preserve an uncluttered appearance inside the housing. The arms 52 and 53 are pivotally connected to each other through rectangular slot 51 in the housing by means of shoulder rivet 56, as best shown in FIG. 6. The spring 54 runs horizontally between shoulder rivet 56 and a small tab 55 on the housing. The inner arm 52 is connected at its free end to the upper portion of the plate 32 of support 30, with the outer arm 53 connected at its free end to the main housing so as to give arm 53 a generally vertical orientation. The two last-mentioned connections are made by pop rivets 58 and 60, the arms fitting over and rotating upon circular protrusions on the surfaces of the housing and supports.

As a given shield support moves up and down, the wheels 31 bearing against the sides of the main housing prevent the support from moving horizontally. Thus, pop rivet 60 and the end of inner arm 52 attached to the support are constrained to move up and down on a single vertical line. Reference is now made to FIG. 7 for the detailed operation of the spring mechanism. FIG. 7 illustrates, by means of dotted lines, three positions of the mechanism. The letters A, B, and C are used to label the three positions of the arms and the upper edge of the support 30, letter A denoting the extended position, letter C the retracted position, and letter B an intermediate position of unstable equilibrium in which the spring 54 has a maximum extension. Beginning with the extended position, the support-attached end of the arm 52 is below the spring-attached end of said arm 52, so that the force of the spring, in view of the horizontal constraint of rivet 60, resists upward movement of the support. The extended position is thus one of stable equilibrium in which the shoulder rivet 56 rests against the vertical edge of slot 51, preventing the support from falling further downward and out of the main housing. As manual upward force is applied to the shield and support, the support-attached end of arm 52 is forced upward. Due again to the horizontal constraint of rivet 60 the springattached end of arm 52 is forced horizontally, extending the spring. When arm 52 becomes horizontal, the extension of the spring is at a maximum; further upward m0- tion of the support-attached end of the arm would bring that end above the spring-attached end, at which point the force of the spring would change to produce an upward rather than downward tendency against the supportattached end of the arm. The result of all this is that position B is one of unstable equilibrium in that the spring tends to reinforce rather than oppose motion of the support in either direction.

Once the support is brought to position B by manual pressure, a further slight upward push causes the springs to take over and bring the support the rest of the way to its retracted position C. Importantly, at the retracted position the spring still applies upward force but this is opposed by the downward force of the ceiling against the flanges 18. To this end, the height of the main housing can easily be adjusted so that the flanges 18 contact the ceiling before the shoulder rivet 56 hits the edge of the slot 51. The force of the spring thus holds the flanges 18 tightly against the ceiling, eliminating any cracks through which undiffused light might escape, and provides a degree of self-adjustability.

One of the striking features of the invention is the fact that no metal or movable parts are required to be incorporated into the shield, thus allowing the entire shield, except for the end pieces, to be formed in a single operation from linearly extruded translucent plastic, greatly decreasing manufacturing costs. The support engaging members 16 of the shield extend from the inverted trough hooking means 20 running along their upper edges, downward and laterally outward along intermediate portions 22 to meet the main transmitting body 14. Members 16 are thus able to include between them a main transmitting body of a width substantially larger than the width of the main housing. Main transmitting body 14 is generally flat, possibly with corrugations or optical prisms on its surface, although other desired shapes may be employed. Flanges 18 extend outward from the main body 14, laterally beyond support engaging members 16, said flanges running along the entire length of the shield. Running parallel to flanges 18 are abutment ridges 24, one such ridge along each long edge of the shield. These ridges 24 are located laterally outward from the support engaging members 16 and extend upwardly from the main transmitting body 14 in order to provide substantially vertical outwardly directed abutment faces 26. Abutment faces 26 are designed to engage the vertical edges of the ceiling recess and thereby aid in the horizontal positioning of the shield. The width of the shield between abutment faces 26 is slightly less than the width of the recess, allowing a slight horizontal freedom of the shield in the installed position. This horizontal freedom is used in the process of removing the shield from the fixture, as described below.

Importantly, support engaging members 16, especially intermediate portions 22, as well as flanges 18, are of light transmitting material. In this manner, light will be carried along members 16 into flanges 18, giving the flanges horizontal surfaces and vertical edges a lighted appearance along the ceiling and locating the line of contrast between light and darkness at the ceiling surface rather than on the shield, enhancing the lighted panel effect.

The precise design of shield end pieces 17 depends upon the use being made of the fixture. If the fixture is being used as a single unit, then the end piece should have a flange 19 similar to flanges 18, overlapping the ceiling. On the other hand, if the fixture is to line up end to end with other fixtures to produce a long strip of lighted ceiling, flanges 19 may be shortened or wholly eliminated as the end to end contact of the shields will provide a continuous shield surface. In either case, the vertical portions of the end pieces 17 are shaped to match a vertical cross section of the shield and are cemented or otherwise attached to the ends of the shield.

To remove the shield it is necessary simply to apply light fingertip pressure to the vertical edge of one of the side flanges on the shield, causing the shield to move horizontally and slightly downward on the side being manipulated. It is then a simple matter to insert the fingers between the ceiling and the shield flange and apply downward pressure, moving the shield and the support to the extended position. By grasping the then obliquely oriented ends of the shield, the other side of the shield is lowered. The shield is removed from one support by the support-flexing technique employed in installation. The shield can then either hang from the other support while the fixture is serviced, or can be removed entirely.

Just as abutment faces 26 aid in the horizontal positioning of the installed shield in one direction, the end caps 13 of the main housing aid in the horizontal positioning of the shield in the other direction by means of inwardly offset portions 15 along the lower edges of said end caps (FIGS. 1, 2). These oifset portions 15 engage vertically tapered strips 23, located at the lower edges of the shield end pieces 17 and resting atop the flange-s 19 (FIGS. 1, 2, 5), in the same manner that the recess edges engage the abutment faces 26.

The main housing is also provided with side stops 62 extending from the sides of the end caps 13 generally perpendicular to the end caps, giving a total of four such side stops. These side stops 62 are positioned with respect to the shield above the grooves between the abutment ridges 24 and the support engaging members 16, and serve the purpose of preventing the shield from pivoting up into the recess should someone attempt to pivot the shield while one side is still in the retracted position.

It will be obvious that numerous modifications of the specific details can be made within the spirit and scope of the invention.

What is claimed is:

1. An elongated fluorescent lighting fixture having a main housing adapted to be installed in a recess in a ceiling with said housing lying entirely above the lower surface of the ceiling,

a light-diffusing shield adapted to be installed in said fixture without external securing means, and

shield supports associated with said shield,

said shield adapted to be installed in said fixture by upward movement toward said housing and to be retained in its installed position by said supports, said shield comprising a main transmitting body located flush with the ceiling when said shield is in said installed position, light transmitting support engaging members mounted along two opposing edges of said main body and extending upwardly and inwardly of said edges to removably engage said shield supports along substantially the entire length of said shield, and light-transmitting flanges exposed to view and extending from said opposing edges of said main body laterally outwardly of said main body beyond said support engaging members, said shield supports comprising elongated plates extending along the sides of said housing spaced inwardly relative to the corresponding edge of said shield and retractably connected by resilient means to said housing and movable between a retracted position in which said overlapping flanges firmly contact the borders of said recess While said resilient means, through said shield supports, exert upward force on said shield thereby holding said flanges tightly against said ceiling, and

an extended position in which said flanges are sufficiently below the ceiling so that, upon disengaging either one of said support engaging members from its corresponding shield support, said shield is pivotal at the other of said support engaging members about its corresponding shield support at an axis spaced below the level of the ceiling and parallel to the shield edge adjacent said other support engaging member to allow the main body of the shield to swing down, While providing clearance for said shield edge to swing up.

2. An elongated fluorescent lighting fixture having a main housing adapted to be installed in a recess in a ceiling with said housing lying entirely above the lower surface of the ceiling, a light-diffusing shield adapted to be installed in said fixture without external securing means and shield supports associated with said shield, said shield having support-engaging means adapted to removably engage said supports, said supports retractably connected by resilient means to said main housing, said resilient means including a first link pivoted at one end to said housing,

a second link pivoted at one end to said shield support and at the other end to the free end of said first link,

a tension spring connected at one end to said housing and at the other end to said links where they are pivoted together,

said links and spring forming an over center spring mechanism with a line of centers located so that upward movement of said shield from its extended position toward said housing increase-s tension on said spring, resisting said movement up to a position of unstable equilibrium spaced below said installed position of said shield, and movement past said position of unstable equilibrium causes said spring tension to urge said shield upwardly to said installed position and hold it there,

said shield supports having guide means slidingly engaging the ends of said housing in all positions of the shield, allowing vertical movement but preventing lengthwise movement of said shield supports, said resilient means being laterally flexible in the ex tended position enabling removal and replacement of said shield. 3. The fixture of claim 2, wherein there are two of said over center spring mechanisms on each side of said housing spaced at opposite ends of said shield.

References Cited by the Examiner UNITED STATES PATENTS 2,806,726 9/1957 Broberg 240146 X 2,826,684 3/1958 Baker 240-147 X 2,869,908 1/1959 Ford 24O-146 X 2,978,574 4/1961 Baker 240-146 3,069,537 12/ 1962 Dayton et al. 24051.l1 3,142,447 7/1964 Bodian 240147 NORTON ANSHER, Primary Examiner.

C. R. RHODES, Assistant Examiner. 

1. AN ELONGATED FLUORESCENT LIGHTING FIXTURE HAVING A MAIN HOUSING ADAPTED TO BE INSTALLED IN A RECESS IN A CEILING WITH SAID HOUSING LYING ENTIRELY ABOVE THE LOWER SURFACE OF THE CEILING, A LIGHT-DIFFUSING SHIELD ADPATED TO BE INSTALLED IN SAID FIXTURE WITHOUT EXTERNAL SECURING MENAS, AND SHIELD SUPPORTS ASSOCIATED WITH SAID SHIELD, SAID SHIELD ADAPTED TO BE INSTALLED IN SAID FIXTURE BY UPWARD MOVEMENT TOWARD SAID HOUSING AND TO BE RETAINED IN ITS INSTALLED POSITION BY SAID SUPPORTS, SAID SHIELD COMPRISING A MAIN TRANSMITTING BODY LOCATED FLUSH WITH THE CEILING WHEN SAID SHIELD IS IN SAID INSTALLED POSITION, LIGHT TRANSMITTING SUPPORT ENGAING MEMBERS MOUNTED ALONG TWO OPPOSING EDGES OF SAID MAIN BODY AND EXTENDING UPWARDLY AND INWARDLY OF SAID EDGES TO REMOVABLY ENGAGE SAID SHIELD SUPPORTS ALONG SUBSTANTIALLY THE ENTIRE LENGTH OF SAID SHIELD, AND LIGHT-TRANSMITTING FLANGES EXPOSED TO VIEW AND EXTENDING FROM SAID OPPOSING EDGES OF SAID MAIN BODY LATERALLY OUTWARDLY OF SAID MAIN BOYD BEYOND SAID SUPPORT ENGAGING MEMBERS, SAID SHIELD SUPPORTS COMPRISING ELONGATED PLATES EXTENDING ALONG THE SIDES OF SAID HOUSING SPACED INWARDLY RELATIVE TO THE CORRESPONDING EDGES OF SAID SHIELD AND RETRACTABLY CONNECTED BY RESILIENT MEANS TO SAID HOUSING AND MOVABLE BETWEEN A RETRACTED POSITION IN WHICH SAID OVELAPPING FLANGES FIRMLY CONTACT THE BORDERS OF SAID RECESS WHILE SAID RESILIENT MEANS, THROUGH SAID SHIELD SUPPORTS, EXERT UPWARD FORCE ON SAID SHIELD THEREBY HOLDING SAID FLANGES TIGHTLY AGAINST SAID CEILING, AND AN EXTENDED POSITION IN WHICH SAID FLANGES ARE SUFFICIENTLY BELOW THE CEILING SO THAT, UPON DISENGAGING EITHER ONE OF SAID SUPPORT ENGAGING MEMBERS FROM ITS CORRESPONDING SHIELD SUPPORT, SAID SHIELD IS PIVOTAL AT THE OTHER OF SAID SUPPORT ENGAGING MEMBERS ABOUT ITS CORESPONDING SHIELD SUPPORT AT AN AXIS SPACED BELOW THE LEVEL OF THE CEILING AND PARALLEL TO THE SHIELD EDGE ADJACENT SAID OTHER SUPPORT ENGAGING MEMBER TO ALLOW THE MAIN BODY OF THE SHIELD TO SWING DOWN, WHILE PROVIDING CLEARANCE FOR SAID SHIELD EDGE TO SWING UP. 